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Timothy B. Crawford - One of the best experts on this subject based on the ideXlab platform.
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intra nasal inoculation of american bison bison bison with Ovine Herpesvirus 2 ovhv 2 reliably reproduces malignant catarrhal fever
Veterinary Pathology, 2007Co-Authors: Donal Otoole, Naomi S Taus, D L Montgomery, J L Oaks, Timothy B. CrawfordAbstract:Sheep-associated malignant catarrhal fever (MCF) due to infection with Ovine Herpesvirus 2 (OvHV-2) is common in commercial herds of American bison (Bison bison). Inability to propagate OvHV-2 in vitro has been a constraint on experimental studies of the disease. We sought to establish whether nasal secretions from sheep that shed OvHV-2 might induce the disease in bison and to define a minimum challenge dose. Fourteen bison were nebulized with sheep nasal sections containing 103–107 OvHV-2 deoxyribonucleic acid (DNA) copies. Most challenged bison (11/14, 78.6%) developed clinical signs at 29–52 days postnebulization (DPN). The mean incubation time was 42.18 (±7.33 SD) DPN. Using real-time polymerase chain reaction, we detected OvHV-2 DNA in peripheral blood leukocytes at 21–31 DPN. All bison that developed MCF had antibodies against the MCF group viruses. Gross and histologic lesions were typical of the acute disease. There was no morphologic evidence of a dose-related difference in the severity or distr...
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a devastating outbreak of malignant catarrhal fever in a bison feedlot
Journal of Veterinary Diagnostic Investigation, 2006Co-Authors: Naomi S Taus, Cevin Jones, Brian G Murphy, James F Evermann, Timothy B. CrawfordAbstract:In early 2003, an outbreak of malignant catarrhal fever (MCF) occurred in a bison feedlot in southern Idaho. The outbreak resulted in a 51.2% (n = 825) mortality rate among bison, which had been exposed to sheep for 19 days. Diagnosis was made by detection of Ovine Herpesvirus 2 (sheep-associated MCF virus) DNA in tissues or peripheral blood by polymerase chain reaction (PCR), and by histological examination of tissue lesions. Peak losses occurred between 41 and 55 days postmean exposure time (PME), and reached a maximum of 41 head per day. No known cases of MCF were observed among the 177 head of bison that arrived in the lot 3 1/2 weeks after the departure of the sheep. Of the several thousand head of beef cattle in the lot during the outbreak, only a single case of MCF was identified. This outbreak illustrates the devastating impact the MCF virus can have on bison under certain exposure conditions, the high threat posed by adolescent lambs to susceptible species, the significantly greater susceptibility of bison than beef cattle to MCF, and the lack of horizontal transmission from clinically affected bison to herdmates.
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malignant catarrhal fever like disease in sheep after intranasal inoculation with Ovine Herpesvirus 2
Journal of Veterinary Diagnostic Investigation, 2005Co-Authors: Hong Li, Lindsay J Oaks, Donal Otoole, Timothy B. CrawfordAbstract:A malignant catarrhal fever (MCF)–like disease was induced experimentally in 3 sheep after aerosol inoculation with Ovine Herpesvirus-2 (OvHV-2). Each of 3 OvHV-2–negative sheep was nebulized with 2 ml of nasal secretions containing approximately 3.07 − 109 OvHV-2 DNA copies from a sheep experiencing an intensive viral-shedding episode. Ovine Herpesvirus-2 DNA became detectable by polymerase chain reaction in the peripheral blood leukocytes of all 3 sheep within 3 days, and all 3 seroconverted between 6 and 8 days postinfection (PI). The sheep developed clinical signs, with copious mucopurulent nasal discharge and fever around 14 days PI. One of the 3 clinically affected sheep was euthanized at 18 days PI. Major lesions at necropsy were multifocal linear erosions and ulcers in mucosa of the cheeks, tongue, pharynx, and proximal esophagus and mild disseminated pneumonia. Microscopically, there was extensive moderate superficial histiocytic–lymphocytic rhinitis with epithelial dissociation and degeneration....
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experimental infection of sheep with Ovine Herpesvirus 2 via aerosolization of nasal secretions
Journal of General Virology, 2005Co-Authors: Naomi S Taus, Donald L Traul, Lindsay J Oaks, Timothy B. Crawford, G S LewisAbstract:Ovine Herpesvirus 2 (OvHV-2) is the causative agent of sheep-associated malignant catarrhal fever in clinically susceptible ruminants, including cattle, bison and deer. Studies of OvHV-2 have been hampered by the lack of an in vitro propagation system. Here, the use of nasal secretions collected from OvHV-2-infected sheep experiencing intense virus shedding episodes as a source of infectious virus for experimental animal infections was examined. OvHV-2 uninfected sheep were nebulized with nasal secretions containing approximately 10(8) to 10(1) copies of OvHV-2 DNA. The time to detectable viral DNA in peripheral blood leukocytes (7-12 days post-infection) and virus-specific antibody in plasma (9-32 days post-infection) varied with the dose of inocula administered. Here, the use of nasal secretions as a source of infectious OvHV-2 was defined and the minimum infectious dose of a pool of nasal secretions that can be used in further studies of viral pathogenesis and vaccine development was determined.
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shedding of Ovine Herpesvirus 2 in sheep nasal secretions the predominant mode for transmission
Journal of Clinical Microbiology, 2004Co-Authors: Naomi S Taus, Donald L Traul, G S Lewis, Okjin Kim, Timothy B. CrawfordAbstract:Ovine Herpesvirus 2 (OvHV-2), the major causative agent of malignant catarrhal fever in ruminant species worldwide, has never been propagated in vitro. Using real-time PCR, a striking, short-lived, peak of viral DNA, ranging from 105 to over 108 copies/2 μg of DNA, was detected in nasal secretions from over 60.7% of adolescent sheep (n = 56) at some point during the period from 6 to 9 months of age. In contrast, only about 18% of adult sheep (n = 33) experienced a shedding episode during the study period. The general pattern of the appearance of viral DNA in nasal secretions was a dramatic rise and subsequent fall within 24 to 36 h, implying a single cycle of viral replication. These episodes occurred sporadically and infrequently, but over the 3-month period most of the 56 lambs (33, or 60.7%) experienced at least one episode. No corresponding fluctuations in DNA levels were found in either peripheral blood leukocytes or plasma. In a DNase protection assay, complete, enveloped OvHV-2 virions were demonstrated in the nasal secretions of all sheep examined during the time when they were experiencing an intense shedding episode. OvHV-2 infectivity in nasal secretions was also demonstrated by aerosolization of the secretions into OvHV-2-negative sheep. The data herein show that nasal shedding is the major mode of OvHV-2 transmission among domestic sheep and that adolescents represent the highest risk group for transmission.
Naomi S Taus - One of the best experts on this subject based on the ideXlab platform.
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a rabbit model for sheep associated malignant catarrhal fever research from virus infection to pathogenesis studies and vaccine development
Current Clinical Microbiology Reports, 2019Co-Authors: Cristina W Cunha, Naomi S Taus, Donald P Knowles, Donal Otoole, Smriti Shringi, Hong LiAbstract:Purpose of Review Describe the implementation and use of rabbits as a laboratory model for sheep-associated malignant catarrhal fever (SA-MCF) research using cell-free Ovine Herpesvirus 2 (OvHV-2). Key considerations regarding the use of the model to generate consistent experimental data are presented and discussed in detail.
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Evaluation of glycoprotein Ov8 as a potential antigen for an OvHV-2-specific diagnostic assay
PLOS ONE, 2018Co-Authors: Salim M. Alhajri, Cristina W Cunha, Hong Li, Donald P Knowles, Naomi S TausAbstract:GammaHerpesviruses in the genus Macavirus establish clinically unapparent persistent infections in reservoir species. Transmission of some of these viruses, including alcelaphine Herpesvirus 1 (AlHV-1) and Ovine Herpesvirus 2 (OvHV-2), to clinically susceptible species in the order Artiodactyla can result in malignant catarrhal fever (MCF), a usually fatal lymphoproliferative disease. Serology can be used to identify MCF virus (MCFV)-infected carrier animals. However, all current serological assays utilize AlHV-1 antigens, thus none is specific for OvHV-2. In situations where sheep and other MCFV carriers are present, such as in zoos and game farms, an OvHV-2-specific assay would determine if OvHV-2 is present in the population. In this study, a recombinant protein containing a truncated OvHV-2 Ov8 glycoprotein was expressed and evaluated as a suitable target antigen to specifically detect OvHV-2 infection using an enzyme linked immunosorbent assay (ELISA). A competitive inhibition (CI)-ELISA that detects an epitope conserved among all MCFVs was used to categorize, as positive or negative, sera from 205 domestic sheep. The Ov8 assay showed 100% diagnostic sensitivity, 98.97% diagnostic specificity, 99.07% positive predictive value, and 100% negative predictive value and very high agreement (kappa = 0.990 and 95% CI = 0.971-1.000) with the CI-ELISA. Sera from animals infected with MCFVs other than OvHV-2 did not cross-react with Ov8 (100% negative predictive value). These data support the use of the Ov8 ELISA as an OvHV-2-specific diagnostic assay.
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Ovine Herpesvirus 2 glycoproteins b h and l are sufficient for and viral glycoprotein ov8 can enhance cell cell membrane fusion
Journal of Virology, 2017Co-Authors: Salim M. Alhajri, Cristina W Cunha, Anthony V Nicola, Hector C Aguilar, Naomi S TausAbstract:Ovine Herpesvirus 2 (OvHV-2) is a gammaHerpesvirus in the genus Macavirus that is carried asymptomatically by sheep. Infection of poorly adapted animals with OvHV-2 results in sheep-associated malignant catarrhal fever, a fatal disease characterized by lymphoproliferation and vasculitis. There is no treatment or vaccine for the disease and no cell culture system to propagate the virus. The lack of cell culture has hindered studies of OvHV-2 biology, including its entry mechanism. As an alternative method to study OvHV-2 glycoproteins responsible for membrane fusion as a part of the entry mechanism, we developed a virus-free cell-to-cell membrane fusion assay to identify the minimum required OvHV-2 glycoproteins to induce membrane fusion. OvHV-2 glycoproteins B, H, and L (gB, gH, and gL) were able to induce membrane fusion together but not when expressed individually. Additionally, open reading frame Ov8, unique to OvHV-2, was found to encode a transmembrane glycoprotein that can significantly enhance membrane fusion. Thus, OvHV-2 gB, gH, and gL are sufficient to induce membrane fusion, while glycoprotein Ov8 plays an enhancing role by an unknown mechanism.IMPORTANCE Herpesviruses enter cells via attachment of the virion to the cellular surface and fusion of the viral envelope with cellular membranes. Virus-cell membrane fusion is an important step for a successful viral infection. Elucidating the roles of viral glycoproteins responsible for membrane fusion is critical toward understanding viral entry. Entry of Ovine Herpesvirus 2 (OvHV-2), the causative agent of sheep associated-malignant catarrhal fever, which is one of the leading causes of death in bison and other ungulates, has not been well studied due to the lack of a cell culture system to propagate the virus. The identification of OvHV-2 glycoproteins that mediate membrane fusion may help identify viral and/or cellular factors involved in OvHV-2 cell tropism and will advance investigation of cellular factors necessary for virus-cell membrane fusion. We found that OvHV-2 glycoproteins B, H, and L are sufficient for, and viral glycoprotein Ov8 can significantly enhance, cell-cell membrane fusion.
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replacement of glycoprotein b in alcelaphine Herpesvirus 1 by its Ovine Herpesvirus 2 homolog implications in vaccine development for sheep associated malignant catarrhal fever
mSphere, 2016Co-Authors: Cristina W Cunha, Alain Vanderplasschen, Benjamin G Dewals, Naomi S Taus, Hong Li, Donald P KnowlesAbstract:ABSTRACT Vaccine development is a top priority in malignant catarrhal fever (MCF) research. In the case of sheep-associated MCF (SA-MCF) caused by Ovine Herpesvirus 2 (OvHV-2), progress toward this objective has been hindered by the absence of methods to attenuate or modify the virus, since it cannot be propagated in vitro. As an alternative for vaccine development, in this study, we tested the hypothesis that one of the SA-MCF vaccine candidate targets, OvHV-2 glycoprotein B (gB), could be expressed by a nonpathogenic alcelaphine Herpesvirus 1 (AlHV-1) and then evaluated the potential of the AlHV-1/OvHV-2 chimera to be used as a vaccine and a diagnostic tool. The construction and characterization of an AlHV-1/OvHV-2 chimeric virus that is nonpathogenic and expresses an OvHV-2 vaccine target are significant steps toward the development of an SA-MCF vaccine and also provide a valuable means to study OvHV-2 biology.
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RESEARCH ARTICLE Cross-Reactivity of Neutralizing Antibodies among Malignant Catarrhal Fever Viruses
2016Co-Authors: Naomi S Taus, Cristina W Cunha, Jana MarquardAbstract:Some members of the gamma Herpesvirus genusMacavirus are maintained in nature as subclinical infections in well-adapted ungulate hosts. Transmission of these viruses to poorly adapted hosts, such as American bison and cattle, can result in the frequently fatal disease malignant catarrhal fever (MCF). Based on phylogenetic analysis, the MCF viruses (MCFV) cluster into two subgroups corresponding to the reservoir hosts ’ subfamilies: Alce-laphinae/Hippotraginae and Caprinae. Antibody cross-reactivity among MCFVs has been demonstrated using techniques such as enzyme linked immunosorbent and immunofluo-rescence assays. However, minimal information is available as to whether virus neutralizing antibodies generated against one MCFV cross react with other members of the genus. This study tested the neutralizing activity of serum and plasma from select MCFV-infected reser-voir hosts against alcelaphine Herpesvirus 1 (AlHV-1) and Ovine Herpesvirus 2 (OvHV-2). Neutralizing antibody activity against AlHV-1 was detected in samples from infected hosts in the Alcelaphinae and Hippotraginae subfamilies, but not from hosts in the Caprinae sub-family. OvHV-2 neutralizing activity was demonstrated in samples from goats (Caprinae) but not from wildebeest (Alcelaphinae). These results show that neutralizing antibody cross reactivity is present to MCFVs within a virus subgroup but not between subgroups. This information is important for diagnosing infection with MCFVs and in the development of vac-cines against MCF
Hong Li - One of the best experts on this subject based on the ideXlab platform.
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a rabbit model for sheep associated malignant catarrhal fever research from virus infection to pathogenesis studies and vaccine development
Current Clinical Microbiology Reports, 2019Co-Authors: Cristina W Cunha, Naomi S Taus, Donald P Knowles, Donal Otoole, Smriti Shringi, Hong LiAbstract:Purpose of Review Describe the implementation and use of rabbits as a laboratory model for sheep-associated malignant catarrhal fever (SA-MCF) research using cell-free Ovine Herpesvirus 2 (OvHV-2). Key considerations regarding the use of the model to generate consistent experimental data are presented and discussed in detail.
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Evaluation of glycoprotein Ov8 as a potential antigen for an OvHV-2-specific diagnostic assay
PLOS ONE, 2018Co-Authors: Salim M. Alhajri, Cristina W Cunha, Hong Li, Donald P Knowles, Naomi S TausAbstract:GammaHerpesviruses in the genus Macavirus establish clinically unapparent persistent infections in reservoir species. Transmission of some of these viruses, including alcelaphine Herpesvirus 1 (AlHV-1) and Ovine Herpesvirus 2 (OvHV-2), to clinically susceptible species in the order Artiodactyla can result in malignant catarrhal fever (MCF), a usually fatal lymphoproliferative disease. Serology can be used to identify MCF virus (MCFV)-infected carrier animals. However, all current serological assays utilize AlHV-1 antigens, thus none is specific for OvHV-2. In situations where sheep and other MCFV carriers are present, such as in zoos and game farms, an OvHV-2-specific assay would determine if OvHV-2 is present in the population. In this study, a recombinant protein containing a truncated OvHV-2 Ov8 glycoprotein was expressed and evaluated as a suitable target antigen to specifically detect OvHV-2 infection using an enzyme linked immunosorbent assay (ELISA). A competitive inhibition (CI)-ELISA that detects an epitope conserved among all MCFVs was used to categorize, as positive or negative, sera from 205 domestic sheep. The Ov8 assay showed 100% diagnostic sensitivity, 98.97% diagnostic specificity, 99.07% positive predictive value, and 100% negative predictive value and very high agreement (kappa = 0.990 and 95% CI = 0.971-1.000) with the CI-ELISA. Sera from animals infected with MCFVs other than OvHV-2 did not cross-react with Ov8 (100% negative predictive value). These data support the use of the Ov8 ELISA as an OvHV-2-specific diagnostic assay.
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sheep associated malignant catarrhal fever like skin disease in a free ranging bighorn sheep ovis canadensis alberta canada
Journal of Wildlife Diseases, 2017Co-Authors: Owen M Slater, Hong Li, Jeanine Peterskennedy, Manigandan Lejeune, David L Gummer, Bryan J Macbeth, Amy L Warren, Tomy JosephAbstract:Abstract Malignant catarrhal fever–like clinical disease was diagnosed in a free-ranging bighorn sheep (Ovis canadensis) from Alberta, Canada, in June 2015. Antemortem and gross pathology findings included muscle atrophy, marked weight loss, and bilaterally symmetric alopecia with hyperpigmentation and crusting over the face, medial surfaces of the pinnae, dorsal trunk, distal limbs, perineal area, and tail. Histologically, the skin lesions were characterized by granulomatous mural folliculitis with numerous multinucleated giant cells and fewer lymphocytes and eosinophils consistent with previous reports of chronic Ovine Herpesvirus-2 (OvHV-2) infection. Multiple skin samples were positive for OvHV-2 DNA on PCR, and on partial sequencing of the viral DNA, there was 94% homology with reference GenBank OvHV-2. Quantitative PCR confirmed an increased level of OvHV-2 DNA in the lesional skin tissues. Based on exclusion of other disease processes, gross and histological lesions, PCR, and viral DNA sequencing r...
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replacement of glycoprotein b in alcelaphine Herpesvirus 1 by its Ovine Herpesvirus 2 homolog implications in vaccine development for sheep associated malignant catarrhal fever
mSphere, 2016Co-Authors: Cristina W Cunha, Alain Vanderplasschen, Benjamin G Dewals, Naomi S Taus, Hong Li, Donald P KnowlesAbstract:ABSTRACT Vaccine development is a top priority in malignant catarrhal fever (MCF) research. In the case of sheep-associated MCF (SA-MCF) caused by Ovine Herpesvirus 2 (OvHV-2), progress toward this objective has been hindered by the absence of methods to attenuate or modify the virus, since it cannot be propagated in vitro. As an alternative for vaccine development, in this study, we tested the hypothesis that one of the SA-MCF vaccine candidate targets, OvHV-2 glycoprotein B (gB), could be expressed by a nonpathogenic alcelaphine Herpesvirus 1 (AlHV-1) and then evaluated the potential of the AlHV-1/OvHV-2 chimera to be used as a vaccine and a diagnostic tool. The construction and characterization of an AlHV-1/OvHV-2 chimeric virus that is nonpathogenic and expresses an OvHV-2 vaccine target are significant steps toward the development of an SA-MCF vaccine and also provide a valuable means to study OvHV-2 biology.
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Cross-Reactivity of Neutralizing Antibodies among Malignant Catarrhal Fever Viruses.
PLOS ONE, 2015Co-Authors: Naomi S Taus, Cristina W Cunha, Jana Marquard, Donal O’toole, Hong LiAbstract:Some members of the gamma Herpesvirus genus Macavirus are maintained in nature as subclinical infections in well-adapted ungulate hosts. Transmission of these viruses to poorly adapted hosts, such as American bison and cattle, can result in the frequently fatal disease malignant catarrhal fever (MCF). Based on phylogenetic analysis, the MCF viruses (MCFV) cluster into two subgroups corresponding to the reservoir hosts’ subfamilies: Alcelaphinae/Hippotraginae and Caprinae. Antibody cross-reactivity among MCFVs has been demonstrated using techniques such as enzyme linked immunosorbent and immunofluorescence assays. However, minimal information is available as to whether virus neutralizing antibodies generated against one MCFV cross react with other members of the genus. This study tested the neutralizing activity of serum and plasma from select MCFV-infected reservoir hosts against alcelaphine Herpesvirus 1 (AlHV-1) and Ovine Herpesvirus 2 (OvHV-2). Neutralizing antibody activity against AlHV-1 was detected in samples from infected hosts in the Alcelaphinae and Hippotraginae subfamilies, but not from hosts in the Caprinae subfamily. OvHV-2 neutralizing activity was demonstrated in samples from goats (Caprinae) but not from wildebeest (Alcelaphinae). These results show that neutralizing antibody cross reactivity is present to MCFVs within a virus subgroup but not between subgroups. This information is important for diagnosing infection with MCFVs and in the development of vaccines against MCF.
Donal Otoole - One of the best experts on this subject based on the ideXlab platform.
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a rabbit model for sheep associated malignant catarrhal fever research from virus infection to pathogenesis studies and vaccine development
Current Clinical Microbiology Reports, 2019Co-Authors: Cristina W Cunha, Naomi S Taus, Donald P Knowles, Donal Otoole, Smriti Shringi, Hong LiAbstract:Purpose of Review Describe the implementation and use of rabbits as a laboratory model for sheep-associated malignant catarrhal fever (SA-MCF) research using cell-free Ovine Herpesvirus 2 (OvHV-2). Key considerations regarding the use of the model to generate consistent experimental data are presented and discussed in detail.
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malignant catarrhal fever in american bison bison bison experimentally infected with alcelaphine Herpesvirus 2
Veterinary Microbiology, 2014Co-Authors: Naomi S Taus, Cristina W Cunha, Donal Otoole, David R Herndon, Janet V Warg, Bruce S Seal, Angela BrookingAbstract:Abstract Malignant catarrhal fever (MCF), due to Ovine Herpesvirus 2 (OvHV-2), causes appreciable death loss in ranched bison ( Bison bison ) throughout North America. No vaccine exists to protect animals from disease. Since OvHV-2 has not been propagated in vitro , one strategy to develop a modified live vaccine is to use a closely related, non-pathogenic member of the malignant catarrhal fever virus family as a vector expressing potentially protective OvHV-2 epitopes. To date, no controlled experimental challenge studies with alcelaphine Herpesvirus 2 (AlHV-2) derived from topi ( Damaliscus lunatus jimela ) have been reported The unique or light DNA segment of the AlHV-2 genome was sequenced and annotated and the virus was tested for its ability to infect and induce disease in American bison. Yearling bison were inoculated intranasally ( n = 4) or intramuscularly ( n = 3) with 2 × 10 −4.7 TCID 50 of AlHV-2, and monitored for infection and the development of disease. Six inoculated bison became infected with AlHV-2. Two of the six animals developed clinical signs and had gross and histological lesions consistent with terminal MCF, which differed in distribution from those in bison with MCF due to OvHV-2. One other animal developed minor clinical signs and had gross and histological pulmonary lesions consistent with early (pre-clinical) stages of MCF. Unmodified low cell culture passage AlHV-2 derived from topi is an unsuitable vaccine vector for the prevention of MCF. However, the annotated genome might be useful in identifying genes which could be deleted to potentially attenuate the virus for bison.
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Ovine Herpesvirus 2 infection in american bison virus and host dynamics in the development of sheep associated malignant catarrhal fever
Veterinary Microbiology, 2012Co-Authors: Cristina W Cunha, Katherine L. Gailbreath, Naomi S Taus, Donald P Knowles, Donal Otoole, David A Schneider, Stephen N White, Christopher J Davies, William C DavisAbstract:Ovine Herpesvirus 2 (OvHV-2) is a gammaHerpesvirus that causes sheep-associated malignant catarrhal fever (SA-MCF), a frequently fatal disease mainly of ruminants. This study was designed to define virus-host dynamics following experimental OvHV-2 infection in bison. A transient peak in viral DNA accompanied by the presence of OvHV-2 ORF25, ORF50 and ORF73 transcripts was observed in lungs only from 9 to 12 days post-inoculation (DPI), suggesting occurrence of viral replication. This initial viral replication was associated with only a subtle increase in transcription of inflammation related genes in lungs and tracheal bronchial lymph nodes, while the level of expression of the majority of immune genes measured remained comparable to uninfected animals. Increasing viral load was observed in the blood and peripheral tissues at 16 and 21 DPI, respectively, indicating systemic viral dissemination. Clinical signs of MCF were observed between 28 and 35 DPI and the severity of lesions increased as disease progressed. Lesion scores were positively correlated with expression levels of ORF25, suggesting a contribution of viral replication in the pathogenesis of SA-MCF. Viral transcripts were observed in all tissues examined from 23 DPI to the end of the experiment at 35 DPI and expression levels of ORF25 were significantly higher in clinically infected animals as compared to pre-clinical stage. The data from this study provide a predictable viral-host interaction time course to test hypotheses concerning disease pathogenesis as well as mitigation of SA-MCF in susceptible species.
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cd8 perforin wc1 γδ t cells not cd8 αβ t cells infiltrate vasculitis lesions of american bison bison bison with experimental sheep associated malignant catarrhal fever
Veterinary Immunology and Immunopathology, 2010Co-Authors: Danielle D Nelson, William C Davis, Wendy C Brown, Donal Otoole, Lindsay J OaksAbstract:Abstract Sheep-associated malignant catarrhal fever (SA-MCF) caused by Ovine Herpesvirus-2 (OvHV-2), a γ-Herpesvirus in the Macavirus genus, is a fatal disease associated with lymphoproliferation, lymphocytic vasculitis, and mucosal ulceration in clinically susceptible species. SA-MCF is an important threat to American bison ( Bison bison ) due to their high susceptibility to this disease. Currently, the pathogenesis of disease in SA-MCF is poorly understood, and the immunophenotype of lymphocytes that infiltrate the vascular lesions of bison and cattle with SA-MCF has been only partially defined. Previous single-color immunohistochemistry studies have demonstrated that CD8 + cells and CD4 + cells predominate within vascular infiltrates in cattle and bison. The CD8 + cells detected in the vascular lesions of cattle and bison were assumed to be cytotoxic αβ T lymphocytes. However, polychromatic immunophenotyping analyses in this study showed that CD8 + /perforin + γδ T cells, CD4 + /perforin − αβ T cells, and B cells infiltrate vascular lesions in the urinary bladder, kidney, and liver of six bison with experimentally-induced SA-MCF. CD8 + αβ T cells and WC1 + γδ T cell cells were only infrequently and inconsistently identified. This study confirmed our hypothesis that the predominant CD8 + lymphocytes infiltrating the vascular lesions of bison with SA-MCF are cytotoxic lymphocytes of the innate immune system, not CD8 + αβ T cells. Results of the present study support the previous suggestions that MCF is fundamentally a disease of immune dysregulation.
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experimental nebulization of american bison bison bison with low doses of Ovine Herpesvirus 2 from sheep nasal secretions
Veterinary Microbiology, 2010Co-Authors: Katherine L. Gailbreath, Naomi S Taus, Donald P Knowles, Donal Otoole, Lindsay J OaksAbstract:Malignant catarrhal fever (MCF), caused by Ovine Herpesvirus 2 (OvHV-2), is an important cause of mortality in ranched American bison and domestic cattle in North America. Previous studies showed that bison can be infected by intranasal nebulization with sheep nasal secretions containing OvHV-2 and provided preliminary information on viral doses required for infection and disease progression. The goals of this study were to establish optimal minimal infectious and minimal lethal doses of OvHV-2 by the intranasal route in bison, evaluate the influence of dose on incubation period and other clinical parameters and determine if bison seropositive for antibody against MCF-group viruses are resistant to developing MCF after intranasal challenge. In this study, the minimal infectious dose and minimal lethal dose overlap, suggesting that experimental production of subclinically infected bison is impractical. Dose is inversely related to both incubation period and the period between nebulization and first detection of >1000 OvHV-2 DNA copies/500 ng total DNA in peripheral blood leukocytes. Interestingly, all of the bison seropositive for anti-MCF-group viral antibody prior to inoculation died of MCF after nebulization. We conclude that previous exposure to an MCF-group virus does not necessarily provide resistance to OvHV-2-induced MCF in bison.
Lindsay J Oaks - One of the best experts on this subject based on the ideXlab platform.
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cd8 perforin wc1 γδ t cells not cd8 αβ t cells infiltrate vasculitis lesions of american bison bison bison with experimental sheep associated malignant catarrhal fever
Veterinary Immunology and Immunopathology, 2010Co-Authors: Danielle D Nelson, William C Davis, Wendy C Brown, Donal Otoole, Lindsay J OaksAbstract:Abstract Sheep-associated malignant catarrhal fever (SA-MCF) caused by Ovine Herpesvirus-2 (OvHV-2), a γ-Herpesvirus in the Macavirus genus, is a fatal disease associated with lymphoproliferation, lymphocytic vasculitis, and mucosal ulceration in clinically susceptible species. SA-MCF is an important threat to American bison ( Bison bison ) due to their high susceptibility to this disease. Currently, the pathogenesis of disease in SA-MCF is poorly understood, and the immunophenotype of lymphocytes that infiltrate the vascular lesions of bison and cattle with SA-MCF has been only partially defined. Previous single-color immunohistochemistry studies have demonstrated that CD8 + cells and CD4 + cells predominate within vascular infiltrates in cattle and bison. The CD8 + cells detected in the vascular lesions of cattle and bison were assumed to be cytotoxic αβ T lymphocytes. However, polychromatic immunophenotyping analyses in this study showed that CD8 + /perforin + γδ T cells, CD4 + /perforin − αβ T cells, and B cells infiltrate vascular lesions in the urinary bladder, kidney, and liver of six bison with experimentally-induced SA-MCF. CD8 + αβ T cells and WC1 + γδ T cell cells were only infrequently and inconsistently identified. This study confirmed our hypothesis that the predominant CD8 + lymphocytes infiltrating the vascular lesions of bison with SA-MCF are cytotoxic lymphocytes of the innate immune system, not CD8 + αβ T cells. Results of the present study support the previous suggestions that MCF is fundamentally a disease of immune dysregulation.
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experimental nebulization of american bison bison bison with low doses of Ovine Herpesvirus 2 from sheep nasal secretions
Veterinary Microbiology, 2010Co-Authors: Katherine L. Gailbreath, Naomi S Taus, Donald P Knowles, Donal Otoole, Lindsay J OaksAbstract:Malignant catarrhal fever (MCF), caused by Ovine Herpesvirus 2 (OvHV-2), is an important cause of mortality in ranched American bison and domestic cattle in North America. Previous studies showed that bison can be infected by intranasal nebulization with sheep nasal secretions containing OvHV-2 and provided preliminary information on viral doses required for infection and disease progression. The goals of this study were to establish optimal minimal infectious and minimal lethal doses of OvHV-2 by the intranasal route in bison, evaluate the influence of dose on incubation period and other clinical parameters and determine if bison seropositive for antibody against MCF-group viruses are resistant to developing MCF after intranasal challenge. In this study, the minimal infectious dose and minimal lethal dose overlap, suggesting that experimental production of subclinically infected bison is impractical. Dose is inversely related to both incubation period and the period between nebulization and first detection of >1000 OvHV-2 DNA copies/500 ng total DNA in peripheral blood leukocytes. Interestingly, all of the bison seropositive for anti-MCF-group viral antibody prior to inoculation died of MCF after nebulization. We conclude that previous exposure to an MCF-group virus does not necessarily provide resistance to OvHV-2-induced MCF in bison.
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experimental aerosol infection of cattle bos taurus with Ovine Herpesvirus 2 using nasal secretions from infected sheep
Veterinary Microbiology, 2006Co-Authors: Naomi S Taus, Donald L Traul, Lindsay J Oaks, Katherine Gailbreath, Donal OtooleAbstract:Infection of clinically susceptible ruminants, including domesticated cattle and American bison, with Ovine Herpesvirus 2 (OvHV-2) can result in the fatal lymphoproliferative and vasculitis syndrome known as malignant catarrhal fever (MCF). A reliable experimental infection model is needed to study the pathogenesis of MCF and to develop effective vaccination strategies to control the disease. An experimental aerosol infection model using sheep, the natural carriers of OvHV-2, has been developed (Taus et al., 2005). Using the protocol and OvHV-2 inoculum established in the previous study, eight calves were nebulized with four different doses of OvHV-2 in nasal secretions from infected sheep. Two control calves were nebulized with nasal secretions from uninfected sheep. Infection status of all calves was monitored using competitive inhibition ELISA, PCR and clinical parameters. Six of eight nebulized calves became infected with OvHV-2. One calf receiving the highest dose of virus developed typical clinical, gross and histological changes of MCF. This study showed that nasal secretions collected from sheep experiencing OvHV-2 shedding episodes were infectious for cattle and capable of inducing MCF. The data also indicate that cattle are relatively resistant to disease following infection. The use of more susceptible species as experimental animal models, such as bison and selected cervid species should be examined.
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a real time pcr assay for measuring alcelaphine Herpesvirus 1 dna
Journal of Virological Methods, 2005Co-Authors: Donald L Traul, Shirley Elias, Lynn M Herrmann, Lindsay J Oaks, Naomi S Taus, Hong LiAbstract:Abstract Alcelaphine Herpesvirus-1 (AlHV-1) is a rhadinovirus that causes malignant catarrhal fever in certain ruminant species and is an important pathogen in Africa and other areas where carrier species and clinically susceptible ruminants intermingle. In this study, a real-time PCR for AlHV-1 DNA was developed and compared to an established nested PCR. The nested PCR amplifies a region of the AlHV-1 gene coding for a transactivator protein (ORF 50), while the real-time PCR assay targets the AlHV-1 gene coding for a tegument protein (ORF 3). The real-time PCR assay reproducibly detected 10 copies of target DNA. In a dilution series of the target DNA there was linearity of the assay across 8 orders of magnitude (101–109 copies). The nested PCR was more sensitive (≅1 log) than the real-time PCR. The assay specifically amplified samples containing only AlHV-1, but not other common Herpesviruses of cattle. In conclusion, we have developed a rapid, relatively sensitive, and reliable real-time PCR assay specific for AlHV-1. Similar to the real-time PCR for Ovine Herpesvirus-2, this assay should prove useful for differential diagnostics of clinical MCF and for research to better define the epidemiology of AlHV-1 in wildebeest as well as in animals with wildebeest-associated MCF.
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malignant catarrhal fever like disease in sheep after intranasal inoculation with Ovine Herpesvirus 2
Journal of Veterinary Diagnostic Investigation, 2005Co-Authors: Hong Li, Lindsay J Oaks, Donal Otoole, Timothy B. CrawfordAbstract:A malignant catarrhal fever (MCF)–like disease was induced experimentally in 3 sheep after aerosol inoculation with Ovine Herpesvirus-2 (OvHV-2). Each of 3 OvHV-2–negative sheep was nebulized with 2 ml of nasal secretions containing approximately 3.07 − 109 OvHV-2 DNA copies from a sheep experiencing an intensive viral-shedding episode. Ovine Herpesvirus-2 DNA became detectable by polymerase chain reaction in the peripheral blood leukocytes of all 3 sheep within 3 days, and all 3 seroconverted between 6 and 8 days postinfection (PI). The sheep developed clinical signs, with copious mucopurulent nasal discharge and fever around 14 days PI. One of the 3 clinically affected sheep was euthanized at 18 days PI. Major lesions at necropsy were multifocal linear erosions and ulcers in mucosa of the cheeks, tongue, pharynx, and proximal esophagus and mild disseminated pneumonia. Microscopically, there was extensive moderate superficial histiocytic–lymphocytic rhinitis with epithelial dissociation and degeneration....
